Assess the controllability, observability, and stability of the following digital system:

\[
\begin{aligned}
\mathbf{x}(k+1) & =\left[\begin{array}{cc}
-1 & 0.8 \\
0.5 & -1.6
\end{array}ight] \mathbf{x}(k)+\left[\begin{array}{l}
1 \\
2
\end{array}ight] \mathbf{u}(k) \\
\mathbf{y}(k) & =\left[\begin{array}{ll}
1 & 0
\end{array}ight] \mathbf{x}(k)+[0] \mathbf{u}(k)
\end{aligned}
\]